[Gluster-devel] Proposal for 3.5: Make adding custom translators easy

[Justin Clift]

Hi all,

For 3.5, I'd like to propose we add a way for people to easily
add custom translators they've written. (using C, or Glupy,
or whatever)

I'm not actually sure (yet) how we'd go about doing it, so
would like to discuss it first before writing things up. :)

As a first thought, maybe we could provide some CLI tooling
to enable this:

  eg: To add a native server side translator written using
Glupy, after the marker translator:

 $ sudo gluster volume $VOLNAME add-translator $TRANSLATOR_NAME \
     $TRANSLATOR_TYPE $FOLLOWING_TRANSLATOR $PATH

Which could be:

 $ sudo gluster volume examplevolume add-translator mycustomone
     server marker /home/jc/mycustomone.py

The CLI would see it's a .py file (therefore Glupy), so it would:
 * Copy the .py file to the Glupy sub-dir
 * Distribute the .py file to the other servers of the volume
 * Ensure the translator is incorporated into the native server
   .vol file after the "marker" translator

It would also need a matching "remove-translator" command.

The downside though... this approach seems like a fairly
complicated way of doing things.  Not really in line with the
concept of keeping Gluster simple for admins.

Maybe we should just have a new install Gluster sub-dir instead,
which takes a .so/.py translator file, and an XML fragment to
say what to do with it.  No CLI.  (would suite deployment via
packaging instead)

Thoughts?

Regards and best wishes,

Justin Clift

--
Open Source and Standards @ Red Hat

twitter.com/realjustinclift